As i noticed lately, the quality of tutorials is sinking slowly.
However, now is the time to put an end to this before it gets worse.

I will make it step by step (every step is individual, so don't push yourself if you are stuck at one point).

Tutorials consist of five main and important points, the design, the head line, the content, the structure and the examples/show offs. Let's start with the content.

~The content

Before you start an tutorial, you have to think about the content. Answers like: "How will I explain it?" and "What will i explain" should be answered. Furthermore, you should think about the aspect of usefullness. "Is it really usefull to explain xyz to asdf-people?".
One more thing, remember this word KISS. It stands for Keep It Short and Simple, if you write your text according you got no problems. If you have cleared the questions above, you have the right to make a tutorial (without getting bothered by guys like me). Now let's step ahead to the next point.

~The design

Design is very important for tutorials, however it is not the most important thing. You have to find the weight between good design and simpleness of the content. An overpowered design with just an text about "why my name is blue and yours is plain white", just destroys the good balance and let's the level of the tutorial sink to near zero. For designs the colour sheme is in my eyes the most important point to think over.
some good shemes:

Black & white

purple & white

a bad examples:

gray & darkgray

you got the point right? The background colour shouldn't be too distracting, the main focus should be on the font colour. Regarding fonts, there is more about them then it seems. You can't just throw out fancy fonts for every situation, that's not the point. Not at all. The content should be simple and easy to understand so the font should be like that as well.

~The headline

The headline should scream out "Hey this is me, i tell you what this is about, so just listen to me and you know what you are reading", in short the headline should tell the user what this is all about. So titels like "How to make epic sprites with epic methods in photoshop and only photoshop, don't bother me for something else cause i don't care" are just too long and contain useless information. Here you can let your creativity explode and put in some fancy fonts, alignments, shadows and what else you have in mind. Moving on to the next point.

~The structure

The structure is really the most important thing in the whole tutorial. Be honest would you like to read something like this:

"Hey this is
my tutorial and
i am pretty happy
about myself"

obviously not~
So keep in mind, structure is important, structure is the one thing which makes your tutorial awesome or just the worst. You have to use paragraphs, lists, punctuation and alignments.

~The examples/show offs

Not everyone out their is a "learning by reading" - type, so plain text won't do. Besides it does make it easier even for the reading-types. Your examples should be simple and easy to understand, the reader should clearly see what you want him to see there. Use circles for instance or underline options. Just draw the attention to the most important part of the example.

~afterword

Thank you very much that you have read to this point, I hope it helped you and the community for a better atmosphere. Now show the world that we aren't just a pack of wolves which fight against each other and make some awesome tutorials